Electric heater.



I No- 896.29' 7. PATENTED AUG. 18, 1908.

E, M. HEWLETT.

ELECTRIC HEATER.

APPLICATION EILED APR. 27, 1907.

3 SHEETS-SHEET 1.

IE5 in" CEIi E-I' Witnesses: Inventor:

evvlett,

No. 896,297. PATENTED AUDG.18, 1908.

B. M. HEWLETT. ELECTRIC HEATER.

APPLICATION FILED APR. 27, 1907.

3 S HEETSSHEET 2.

W tnesses: lnventor:

yaw

E M. HEWLETT.

ELECTRIC HEATER.

APPLICATION FIL ED APR..27,1907.

PATENTED AUG. 18, 1908.

3 SHBETSSHEBT 3.

Fig.6

1" I K H /4 Fig.7

Wines?? I Inventor:

Edwar .levvlett,

vention are capab UNITED srnrrizs PATENT OFFICE.

EDWARD M. HEWLETT, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

. ELECTRIC rmA'rnn.

To all whom it may concern:

Be it known that I, EDWARD M. HEWLETT, a citizen of the United States, residing at Schenectad county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric Heaters, of which the following is a specification This invention relates to resista-r-ice- 'de vices for electric circuits and has for its ob,- ject the rovisionlof a device of this character whic is of a simple and durable construction and at the same time thoroughly reliable and efficient.

My invention relates more specifically'to resistance devices for use in electric heaters or the like althou h certain phases of my ine of a Wider application. One of the objects of my invention is to provide an electric atmospheric heater or radiator, which is intended to be operated at a relatively low heat and canbe brought up .to its working temperature in a comparatively short time.

Another object of my invention is to produce an electric heater which may be constructed at a very low cost, the parts being almost entirely of sheet metal and the re sistance elements themselves being punchings which may be easily assembled and dura ly constructed. a

' Other objects of my invention will appear in the course of-the following specificatlon in which I have set forth my invention in a specific form for ur oses of illustration.

My invention v rt er consists in the features of construction and in the arrangement and combination of elements hereinafter set' forth and particularly pointed' out in the claims annexed hereto.

In the drawings in which I have shown one form of my invention, Figure 1 is a plan view of my heater with the top removed; Fig. 2 is a side elevation of the same with a portion of the inclosing casing broken away; F'g. 3 is a central sectional elevation of the heater; Figs. 4 and '5 show the resistance unit in detail; Figs. 6, 7, 8 and 9 show the process of for'me ing the resistance unit; and Fig. 10 is adiagrain of the circuits;

sectionsaef the heater is identicahand con- Specification of Letters Patent.

' Patented Aug. 18, 1908.

. Application filed April 2"/, 1907.' Serial No. 370,591.

sists of vertical parallel bars 10 and 11 having oppositely flanged ends secured between the top and bottomstrips 12 and 13. These bars constitute the framework to which the rebentback" and forth on itself between the supporting bars of the framework. The strip is preferably in a zigzag or grid-shaped form as shown in Fig. 6. It is made in the continuous strip shown preferably by punching from sheet metal, the perforations beingformed along one edge for purposes hereinafter described. I have also shown the edge opposite the perforations as bent at a slight angle. In adaptin this resistance grid to a radiator I bend or oldit back and forth upon itself so that it lies in parallel sections.

In'order to get the most efficient distristruction, the sections of the strip are arranged on opposite sides of a centre support. To arrange the strip so that the sections may be mounted on the central support I bend it back on itself so that one edge is other edge lies on both sides of the overon itself the holes or perforations 14 along the edge come opposite or into register with each other in the overlapping sections thereby providing a convenient method of securing the sections in place. The strip is bent back onitself in this way by two steps or bendings. At the point where it is desired to bend the strip it is first bent across one of the ends of the an angle of 180 so that the sections are in the relative positions shown in Fig. 7. then bent along the line 16, through 180 in the direction at right angles to the plane of the first bending so that the sections will be as shown in Figs. 8 and 9. The stri) may be bent back and forth upon itself in this way so as to make as many sections as is l osirable. In the present instance the strip is bent back and forth so as to make eight parallel portions each composed of two sections of the strip. The strip after it is bent in this form is mounted between the bars 10 and 11 by means of the rods 17' arranged so as to pass through the perforations 14 in the strip. An insulating sleeve 17 separates the rod 17 from the strip. There are shown six of these bars engagingthe strip slstance units are secured. The resistance bution of heat and a highly desirable con- 1 adjacent to or overlaps upon itself while the grids or line 15 through.-

lapping line, i. (2., when the strip is bent back It is It will be seen that throughout its length. For spacing the adjacent overlapping edges of the strips apart, I provide insulating Washers 18 of porcelain or the like which are adapted to fit over the end of the. rod.

As shown in the drawing the washer is inserted on the rod between the overlapping ends of the strips and the whole is made solid preferably by nuts on the ends of the rods. the resistance units and is left open at the top and'bottom while a hood 20 is raised a short distance above the casing and bent down in the form shown so as to allow the heat to-pass up through the bottom of the casipdig and then deflect downward and out. war

The two divisions of the heater A and B may be arranged so as to get different. de-

grees' of heat either by connecting them in parallel circuits as shown in Fig. 10 or in any desired manner so as to get any regulation of heat required. Electrical connections to the radiator are preferably at the bottom as shown at 21, although any desired method of connecting the device can be resorted to without departing from the spirit of my mvention.

I l -I have produced a very novel and efficient heater which will come up to its working temperature in a comparatively short time in a very simple manner, the resistance unit. being formed of a continuous strip. It requires very little labor in its construction and will stand rolghusage without injury.

arious modifications both as to the radiator itselfand' the form of the resistance I I unit willsug est themselves to those skilled in, the' art all of which I consider is within "thespirit of my invention in'so far as they fall Withinthe scope 6f the claims annexed a extendingiiniopposite'jdirections therefrom.

support and a' jplurality of parallel grid- 9 hereto. I '-What I claim'as new and desire to secure by Letters Patent of'the United States, is, 1. electric heaterscompr'ising a central support and ja plurality of parallel gridshapedresistance strips secure thereto and 12! electric heatercomprising a central shapedf'r'esistance Strips arranged in rows on Ametallic casing.19 surrounds I parallel sections.

0 posite sides of said support and secured t ereto.

3. Anelectric heater comprising a continuous grid-shaped resistance stri folded back and forth upon itself in paralle sections, and means for supporting the said sections.

4. An electricheater comprising a central support and a continuous grid-shaped resistance strip secured thereto and bent back andforth on opposite sides of said support in 51 An electric heater comprising a central support and a plurality of parallel gridshaped resistance strips arranged. in rows and secured on opposite'sides of said support, the opposite strips being cross connected alternately at their opposite ends.

6. A resistance unit comprising a flexible grid-shaped resistance strip folded so that one edge overlaps'itselfand the other edge lies'on both sides of the overlapping edges.

. 7 A resistance unit comprising a flexible grid-shaped resistance stri folded back and overlapping edges, andmeans for supporting and spacm the overlapping edges.

' 10.-An e ectric heater comprlsing a flexible grid-shaped resistance strlp folded back and forth 'so, that one edge overla s itself while the other lies on both sides of t 6 overlapping edges,'a su porting rod extending transversely of sai v edges, and insulating washers thereon for spaclng and securing the fdlds of the stri s.

In witness w ereofpI have hereunto set my hand this 25th day of April, 1907.

' EDWARD M. HEWLETT.

YVitnesses: l

BENJAMIN B.' HULL,

, HELEN Onronn. 

